Multiplex film and process of making



Sept. 1, 1931; L. "r. TROLAND HIULTIPLEX FILM AND PROCESS OF mm Filed June 15, 1.929

v rars ww'rqe ya Patented Sept. 1, 1931 UNITED STATES PATENT OFFICE LEONARD T. TROLAND,

MOTION PICTURE CORPORATION, MAINE KULTIPLEX OF CAMBRIDGE, MASSACHUSETTS, ASSIGNOR TO TECHNIUULQELL OF BOSTON,

MASSACHUSETTS, A CORPORATION or FILM AND PROCESS or MAKING Application fled June 15, 1929. Serial No. 871,151.

of images.

ose of illustrating the genus For the purp of the invention a typical embodiment is g drawings, in

shown in the accompanyi which:

Fig. 1 is a tical system;

Fig. 2 is a side view of the shutter shown in cross section in Fig. 1; and

Fig. 3 is a plan view ofa section of film exposed with the optical system shown in Fi l.

he particular optical system chosen for the purpose of illustration comprises a prism unit consisting of two prisms and P with a light-dividing surface I) therebetween, a shutter S and a suitable objective lens 0 .for focusing images upon the film F. The light-dividing surface D may be formed in any suitable'way as by a light coating of silver adapted to divide the main beam of light along the axis M in two similar beams along the axes (Z and d. While the light may be unequally divided at the surface for most purposes it is preferable to make the divisions substantially equal.

Color filters 1 and 2 are mounted in the paths of the divided beams so that the images I and 1 formed by the divided beams of light re resent different color aspects of the objecteld; and owing to the fact that the light forming image I is reflected only once at the total-reflecting surface 3 whereas the light forming image I is reflected twice, once at the partial reflecting surface 1) and once at the total reflecting surface 4, 50 the images I and I" are reversed with respect diagrammatic view of an o'pto each other, as indicated by the arrows. While these images may be focused upon separate films traveling along parallel paths (perpendicularly to the paper in Fig. 1), it is advantageous film traveling along a path successively iii-- tersecting the two beams (Z and cl so that the images are reversed other longitudinally side of the film. images of each pair with respect to register-- ing 0 enings or notches in the film at or near the line midway between the two images, shrinkage or contraction of the film cancels of the film on the same in subsequent operations so that the images 1 may be printed in exact superposition or otherwise in exact registry with each other.

A characteristic feature of the optical system consists in that the paths of the divided; beams are exactly alike, both in air and in glass, so that the two images I and it are geometrically identical. Another important characteristic consists in that the major tion of the space between the objective lens and the film is filled with a solid mass of glass.

According to this invention the shutter is provided with two windows 5 and 6 in which are mounted filters for absorbing tain components of the light of the main beam. The shutter is mounted to rotate about the axis 7 in synchronism with the in" termittent feed of the film F so that the fil ters 5 and 6 are in the path of the main beam during the exposure of the film to alternate pairs of pictures respectively. Thus four different color aspects of the obj ect-field may be separately photographed on the film corresponding to the following combinations of color filters-1-5, 2-5, 1-6, Obviously the color aspects recorded on the film will depend upon the characteristics of the filters, which in turn may be variously predetermined in accordance with the judgment of the maker. However, for three-color work suitable colors for the filters 1, 2, 5 and 6 are minus green, green, minus red and minus blue, which will hereafter be referred to as G, G, R and -B With this CO1 bination of filters the picture to focus them on the same with respect to each.

Thus by registering the a formed at I through filters 1 and 5 represents the blue aspect the object-f 1d, the picture formed at I thr filters 2 and 5 represents the green aspect ot the objecufield, the picture formed at I through filters 1 and 6 represents the red aspect, and the picture formed at I through filters 2 and 6 also represents the green aspect. For four-color work the filter 2 is preferably minus red instead of green, in which case the image formed at 1 through filters 2 and 5 will represent the fourth color aspect blue-green instead of green. Of the many different filters available the best combination of which I am aware comprises Wratten 43 for minus red, lVratten 32 for the minus green and a Viratten 9 or 12 for the minus blue. In this connection it will be understood that throughout the specification and claims the terms red, green and lue are not intendedto connote exact colors ut are intended merely to connote colors in which these particular hues are predominant or largely characteristic.

eferring to Fig. 3 the images are represented by the letter F to show that the images of each pair RG and BG-B) are reversed with respect to each other longitudinally of the film, the images R and G constituting one pair exposed simultaneously through the minus blue filter 6 for example, BG and G another pair exposed simultaneously through the minus red filter 5 for example, etc, the four images R, G, BG and B together constituting one complete set of images, and the images B and represent-- ing the first and last images of corresponding images. If onl three-color cts are desired one image ifor example i. is b ue-green image) of each set need not be r *oduced and, when using two films traveling at right angles to the path of the film F in vl .ig. 1, only one of images may be formed on one of the two films, in which case it pr "Lrahly advanced one pi ture space at a time {instead of two as in the case of the other film} and an auxiliary shutter may be provided between the prism and the film to out off the light while one of the two filters 5 or 6 is in the path of the main beam (th minus red filter 5 in case the bluegrcen aspect is not desired).

in the case of rapidly n'ioving objects the pictures formed through the filters 5 and 6 at successive intervals of time will not register prec' cly, resulting in a tendency toward color .iuge but by taking the red and eon records sii'nultancously they will register exactly and when using only a single additional color such as blue, fringes will not he ncticea hie for the reason that the blue rec- 0rd, whichcis colored yellow in thefinal picture, does not contribute largely to the defiuition of the picture; and to lesser degree each path, and

in its main path,

same is true of the blue-green record in the four-color example.

For certain purposes only one filter may be used in shutter S, the space for the other filter being left open, in which case three or four different color aspects may herecorded inasmuch as each image is recorded through a different combination, via, 1. 2, l with 5 or 6 and 2 with 5 or 6.

claim:

1. The art of making cinematographic film bearing complemental images of the object field which comprises exposing different areas through different filters in series, each of two filters functioning alternately in series with each of two other filters.

2. The art of making cinematographic three or more images of the object-field along two paths which comprises exposing two of the images through different filter combinations, changingone of the combinations, and subsequently exposing another image along one of the path.

3. The art of making cinematographic film bearing three or more images of the objectfield along two paths which comprises exposing two of the images through different filter combinations, changing the combination for subsequently exposing two more images along the same path, whereby each image represents a different color aspect of the object-field.

. he art of making cinematographic till i bearing tiree complemental images of the object-field which comprises dividing a main image-bearing beam into component beams incident to the film along branched paths, simultaneously exposing two images 0 each set in said paths respectively, alternately exposin a third image of each set along one of said paths, and differently filtering the beams for each of said images, the filter in the path of one beam being changed etween successive exposures.

5. The art of making cinematographic film bearing three complemental images of the object-field which comprises focusing a beam dividing the beam along branched paths, simultaneously exposing two images of each set in the branched paths respectively, alternately exposing a third image of each set along one of said branched paths, filtering the beams in each of said paths, and changing the filter in one path be tween successive exposures of the images of each complemental set.

6. The art of making cinematographic iilm bearing compleme tal images of the objectfield which comprises dividing a beam of light, acting upon the beam of light concomitantly to bring ,ima' es of the object-field a into focus from the same point of view in respective divisions ic beam on cinematographic him, trans 1 ing the respective clineencsc visions of the beam to the film through optically like paths, successively exposing new areas of the film focal plane of each image to form two series of images comprising recurrent pairs of images exposed simultaneously, alternately exposing the film along one of said paths in the interims between said exposures to form another series of images, and filtering out color components differently for the images of each of said series, thereby to obtain successive sets of images representing at least three different color aspects of the object-field.

7. The art of making cinematographic film bearing complemental images of the objectlield which comprises dividing a beam of light, actin upon the beam of light concomitantly to iiiring images of the object-field into focus from the same point of view in respective divisions of the beam in mutually reversed relationship to each other on cinematographic film, transmitting the respec tive divisions of the beam to the film through optically like paths, successively exposing new areas of the film in the focal plane of each image recurrently to form pairs of ima es, i and filtering out color components of light differently for the images of each pair and differently for alternate pairs, thereby to obtain successive sets of images representing four different color aspects of the object-field.

8. The method of making cinematogra hic film bearing series of multiplex images 0 the same object-field comprising dividing a beam of light, acting upon the beam of light to bring images of the object-field into focus from the same point of view in respective divisions of the beam in mutually reversed relationship to each other and side to side on the same side of the film, simultaneously exposing areas of the film through different filters to form pairs of images representing three color aspects oi the object-field and alternately exposing other areas to still a dif' ferent color aspect.

9. The method of making cinematographic film bearing series of multiples. images of the same object-field comprisin dividing a beam of light, acting u on the of light to bring images of to object-field into focus from the same point of view in respective divisions of the beam in mutually reversed re lationship to each other and side to side on the same side of the film, simultaneously posing areas of the film to red and green com ponents of said divisions respectively and alternately exposing other areas to the blue component of one of said tivisions.

10. The method of mah multiplex cinematographic film which c prises causing incidence of a beam of light converging to an image obliquely upon a part1 etlecting and partly transmitting plane ace form similar divides, image-forming mitting the divided beams divergentl like paths symmetrical to each ctlr ly to the plane of the partially re face to form images in reversed rt each other about a line parallel to ma fi'lfl the images, feeding film transver i paths in the image planes of said ing beams, simultaneouslf;- GIipOSl the film through difierent filters natelyexposing other areas through. another filter.

11. The method of making multiples: c' matographic film which comprises can incidence ota beam of light convergin an image obliquely upon a partly roller." and partly transmitting plane surface form similar divided image-i ng beat transmitting the divided beams divergen along like paths symmetrical. to each 0. relatively to the plane of the partially fiecting surface to form image in revo relation to each other about a line paral margins of the images, feeding iilm t versely of said paths in the im plane: said image-forming beams, simultaneou i exposing areas of the film to red and components of said divided beams respective ly and alternately exposing othe i blue component oi one of said t i 12. cinematographic film having three s5- ries of complement-all images presenting difierent color respect th. ages or two of the series repre g comitant timeaspects of the obj the images of the other series re time aspects alternating with those 0 first two.

l3. Ginematographic film having seri; complemental records representing green and blue color aspect-s r red and green records representing ennuiu neous aspects and the blue records repre ing alternate aspects.

14. Cinematographic film having series oi complemental records representing red, green and blue color aspects respectively, red and green records representing si neous aspects and being reversed with .uto each other, and the blue records rcpr ing alternate aspects.

l5, Ginematographic film having a ity of series of complemental images, two ages of each complemental set being c from the same point of view at the same i image of each set being t e point of view at a atographic film having o complemental ime nplemental set bein of view at tile san 'ith respect to cool of each set being int oi view at a sir l..

images i from the and being re v and a this 4 from the 17. Cinematographic film having a series of complemental records representin red, green and blue color aspects respective y, the red and green records representing simulta- 5 neous aspects from the same point 01 View along equal paths and the blue records representing alternate aspects.

18. The art of making cinematographic film having three complemental series of images which comprises simultaneously exposing corresponding images of the red and green series from the same point of View substantially equidistantly from the objective measured along the path of light to the re- 1 spective images, and alternately exposing images of the blue series. I 19. The method of making three-color cinematographic pictures Which com rises recurrently exposing, through a suitab e 0ptical system, pairs of records representing two color aspects from the same point of view and approximately equidistant from the plane Where light enters the'optical system measured along the path of the light to the respective records, and alternately forming a third record representing another color aspect.

20. The method of making three-color cinematographic pictures which comprises an recurrently exposing, through a suitable optical system, pairs of records representing two color aspects from the same point of view and approximately equidistant from the plane Where light enters the optical system measured along the path of the light to the respective records, and alternately forming a third record representing a blue aspect.

Signed by me at Boston, Massachusetts, this 12th day of June, 1929. LEONARD T. TROLAND. 

